Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Biol Open. 2023 Mar 15;12(3). doi: 10.1242/bio.059746. Epub 2023 Feb 28.
Ocean acidification (OA) resulting from anthropogenic CO2 emissions is impairing the reproduction of marine organisms. While parental exposure to OA can protect offspring via carryover effects, this phenomenon is poorly understood in many marine invertebrate taxa. Here, we examined how parental exposure to acidified (pH 7.40) versus ambient (pH 7.72) seawater influenced reproduction and offspring performance across six gametogenic cycles (13 weeks) in the estuarine sea anemone Nematostella vectensis. Females exhibited reproductive plasticity under acidic conditions, releasing significantly fewer but larger eggs compared to ambient females after 4 weeks of exposure, and larger eggs in two of the four following spawning cycles despite recovering fecundity, indicating long-term acclimatization and greater investment in eggs. Males showed no changes in fecundity under acidic conditions but produced a greater percentage of sperm with high mitochondrial membrane potential (MMP; a proxy for elevated motility), which corresponded with higher fertilization rates relative to ambient males. Finally, parental exposure to acidic conditions did not significantly influence offspring development rates, respiration rates, or heat tolerance. Overall, this study demonstrates that parental exposure to acidic conditions impacts gamete production and physiology but not offspring performance in N. vectensis, suggesting that increased investment in individual gametes may promote fitness.
人为 CO2 排放导致的海洋酸化（OA）正在损害海洋生物的繁殖。虽然亲代暴露在酸化环境中（pH7.40）可以通过物质传递效应来保护后代，但在许多海洋无脊椎动物类群中，这种现象还不太清楚。在这里，我们研究了亲代暴露在酸化（pH7.40）与环境（pH7.72）海水中如何影响六次配子发生周期（13 周）中河口海葵 Nematostella vectensis 的繁殖和后代表现。在酸性条件下，雌性表现出繁殖可塑性，与暴露 4 周后的环境雌性相比，释放的卵子数量显著减少但体积更大，并且在接下来的四个产卵周期中的两个中释放的卵子更大，尽管恢复了生育能力，这表明长期适应和对卵子的更大投资。在酸性条件下，雄性的繁殖力没有变化，但产生了更高比例具有高线粒体膜电位（MMP；运动性升高的替代指标）的精子，这与相对于环境雄性更高的受精率相对应。最后，亲代暴露在酸性条件下并没有显著影响后代的发育率、呼吸率或耐热性。总的来说，这项研究表明，亲代暴露在酸性条件下会影响配子的产生和生理特性，但不会影响 N. vectensis 的后代表现，这表明对单个配子的更大投资可能会促进适应度。
